Tamper-resistant container closure having auxiliary removal features

Abstract

To prevent tampering with the contents of containers, the neck of the container is formed with external beads with grooves under the lower surfaces of the beads. The cap has an outer skirt formed with internal beads which lock under the shoulders of the neck beads. Preferably, the cap has an inner skirt which seals against the inside of the container neck. To remove the cap, a score-line is formed extending upward from the bottom edge of the skirt and merging with a horizontal scoreline located between the two internal beads, so that one may grip a tab on the lower edge of the skirt, pull upward on the substantially vertically section and thence horizontally around the horizontal scoreline. Unless the skirt is thus torn, it cannot be removed from the neck and tearing of the skirt indicates tampering with the contents of the container. In the present invention, instead of the horizontal scoreline continuing around the periphery of the cap, it terminates at an unscored area which connects the upper and lower portions of the skirt. The lower portion of the skirt may be gripped by the user as an auxiliary means of removing the cap. The primary means of removing the cap is a flange which extends outward from the top of the cap skirt and may be gripped by the finger and/or thumb to pull the cap off the neck.

What is claimed is: 
     
       1. A plastic cap for sealing a container neck having a top finish comprising a top disc having a depending skirt, said skirt having first bead means extending around the inside of said skirt spaced downward from said disc, second bead means extending around the inside of said skirt spaced downward from said first bead means, a first scoreline between said first and second bead means, said first score-line extending only partially around said skirt with an unscored area of between 10 and 180 degrees arcuate length at the end of said first score-line, a second scoreline extending up from the bottom edge of said skirt and merging with said first score-line, tear means on said bottom edge adjacent said second score-line, whereby by pulling said tear means the bottom of said skirt may be torn by tearing upward along said second score-line and then around said first score-line to the end of said first scoreline and thereby to release said second bead means from said top finish, the portion of said skirt below said first scoreline remaining attached to the upper portion of said skirt at said unscored area, said first and second bead means being engageable with third and fourth bead means, respectively, on the exterior of said neck to resist removal of said cap without tearing said skirt up to said unscored area, the portion of said skirt below said first scoreline comprising gripping means for pulling said cap off said neck by stretching said skirt to release said first bead means from said third bead means. 
     
     
       2. A cap according to claim 1 which further comprises a thin peripheral flange around the top of the exterior of said skirt, said flange comprising means to pry off said cap only when said skirt has been torn along said first score-line up to said unscored area. 
     
     
       3. A cap according to claim 2 in which the underside of said flange slants downward-inward to merge with the exterior of said skirt. 
     
     
       4. A cap according to claim 2 in which said underside of said flange terminates below the top of said flange to form a short, vertical edge for said flange. 
     
     
       5. A cap according to claim 2 in which the underside of said flange extends inward to form a sharp corner at the exterior of said skirt, whereby if one attempts to pry up on said flange said cap tears upward-inward from said corner to indicate tampering. 
     
     
       6. A cap according to claim 1 which further comprises a second skirt depending from said top disc inside said first-mentioned skirt. 
     
     
       7. A cap according to claim 1 in which at least one of said bead means is interrupted to form bead sections with gaps between said bead sections. 
     
     
       8. A cap according to claim 1 in which said first bead means is interrupted to form first bead sections with first gaps between said first bead sections and said second bead means is interrupted to form second bead sections with gaps between said second bead sections. 
     
     
       9. In combination, a plastic cap and a container neck, said cap comprising a top disc having a depending skirt, said skirt having first bead means extending around the inside of said skirt spaced downward from said disc, second bead means extending around the inside of said skirt spaced downward from said first bead means, a first score-line between said first and second bead means, said first scoreline extending only partially around said skirt with an unscored area of between 10 and 180 degrees arcuate length at the end of said first score-line, a second score-line extending up from the bottom edge of said skirt and merging with said first scoreline, tear means on said bottom edge adjacent said second scoreline, whereby by pulling said tear means the bottom of said skirt may be torn by tearing upward along said second scoreline and then around said first score-line to the end of said first score-line and thereby to release said second bead means from said neck, the portion of said skirt below said first score-line remaining attached to the upper portion of said skirt at said unscored area, said container neck comprising a top neck finish, external third and fourth bead means on the exterior of said neck in a position to engage said first and second bead means to resist removal of said cap without tearing said skirt up to said unscored area, the portion of said skirt below said first scoreline comprising gripping means for pulling said cap off said neck by stretching said skirt to release said first bead means from said third bead means. 
     
     
       10. A combination according to claim 9 which further comprises an external shoulder on said neck positioned to fit tightly under the lower edge of said skirt to impede attempts to pry the lower edge of said skirt upward, the width of said shoulder being approximately equal to the thickness of said skirt.